<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .container {
      position: fixed;
      width: 500px;
      height: 500px;
      z-index: 222;
      user-select: none;
    }
    img {
      width: 100px;
      height: 100px;
    }
    .modal {
      position: fixed;
      width: 100%;
      height: 100%;
      background-color: rgba(0, 0, 0, 0.5);
    }
    
  </style>
</head>

<body>

  <div class="container">
    <div class="modal">
    </div>
  </div>
</body>

</html>